Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/frame/PageConsole.cpp

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 35 matching lines @@
 
 }
 
 PageConsole::PageConsole(FrameHost& frameHost)
     : m_frameHost(frameHost)
 {
 }
 
 void PageConsole::addMessage(MessageSource source, MessageLevel level, const String& message)
 {
-    addMessage(source, level, message, String(), 0, 0, 0, 0, 0);
+    addMessage(source, level, message, String(), 0, 0, nullptr, 0, 0);
 }
 
 void PageConsole::addMessage(MessageSource source, MessageLevel level, const String& message, PassRefPtr<ScriptCallStack> callStack)
 {
     addMessage(source, level, message, String(), 0, 0, callStack, 0);
 }
 
 void PageConsole::addMessage(MessageSource source, MessageLevel level, const String& message, const String& url, unsigned lineNumber, unsigned columnNumber, PassRefPtr<ScriptCallStack> callStack, ScriptState* state, unsigned long requestIdentifier)
 {
     if (muteCount && source != ConsoleAPIMessageSource)
@@ skipping 47 matching lines @@
     muteCount++;
 }
 
 void PageConsole::unmute()
 {
     ASSERT(muteCount > 0);
     muteCount--;
 }
 
 } // namespace WebCore